crusade

n.

1706, respelling of croisade (1570s), from Middle French croisade (16c.), Spanish cruzada, both from Medieval Latin cruciata, past participle of cruciare "to mark with a cross," from Latin crux (genitive crucis) "cross." Other Middle English forms were croiserie, creiserie. Figurative sense of "campaign against a public evil" is from 1786.